It can be useful to know when to expect these major announcements. Reporters need to mobilize at a moment's notice to cover the unveiling; rival campaigns need to react quickly with a well-placed counterattack and get started on opposition research. As for the rest of us? We just need to know when we should be monitoring Twitter and tracking airplanes.

As usual, if you want to predict future behavior, look at past behavior. To that end, I've compiled data on the announcement dates of all vice-presidential reveals since 1972. Here they are:

Historically, VP announcements have always happened between July 6 and August 29. Democrats' median announcement date is July 13; Republicans' is August 11. But that's a flawed way to look at it. The announcement dates have varied so wildly because the main event of the summer—each party's convention—is held at a different time each year. We learn a lot more by looking at announcement dates relative to the convention's timing.

Historically, the vice-presidential candidate (not to mention, going even farther back in time, the presidential candidate) has been chosen and announced at the convention itself. This was true in 1972, 1976, 1980, and for Republicans in 1988. Recently, though—starting with an innovation by Walter Mondale in 1984, when he picked Geraldine Ferraro four days before the convention in an historic stunt—parties have decided to spread out their big news events and announce the bottom of the ticket in advance. This trend makes it unlikely that we'll have to wait until either convention to know who the running mates will be—despite Trump's public flirtation with a primetime convention-week reveal.

However, the winner of the veepstakes is still frequently announced just before the convention. The vice-presidential pick was unveiled the week before the convention in 1984 by Democrats, in 1988 by Democrats (six days before the DNC started), in 1992 by Democrats (four days before), in 1996 by Republicans (three days before the RNC), in 2000 by Democrats (seven days before), in 2000 by Republicans (seven days before), in 2008 by Democrats (two days before), and in 2008 by Republicans (three days before). The median BC (Before Convention) announcement date is four days before for Democrats and three days before for Republicans. One week before each convention would thus seem like a pretty likely time to expect an announcement.

But is there a new trend developing in veep selection timing? Twice now, and both in recent history, the running mates have been announced well before the convention: in 2004 by Democrats (20 days before the DNC started) and in 2012 by Republicans (16 days before the RNC started). Of course, this is a small sample size; we probably can't know whether these are just exceptions or the next logical step in the progression of moving the VP selection farther and farther away from the conventions. But we can make a couple observations.

First, no running mate has ever been tapped more than three weeks before the start of a convention. That means it would be unprecedented for the Republican vice-presidential nominee to be announced this year before June 28 or the Democratic nominee to be announced before July 5. So I'd say you can safely stay off the grid until then without fear of missing anything.

Second (and, again, small-sample-size caveats apply), both of those campaigns ended up losing in November. In 2012, Mitt Romney's early selection of Paul Ryan was widely seen as an attempt to change the narrative of his campaign at a time when Romney wasn't exactly having his best week. This could suggest that Trump, whom everyone agrees is losing so far in 2016, could try the same tactic: seize control of the news cycle away from his poor fundraising and controversial statements by announcing his vice-presidential candidate early.

If I were a betting man, I might view this as the most likely of all the possible outcomes. If precedent pretty much mandates that Trump is not going to wait until the convention, it makes strategic sense for him to announce sooner rather than later. I'll make my prediction that Trump will announce his VP as soon as this coming week: on Friday, July 1, heading into the holiday weekend, so people can chew it over along with their hot dogs. (Since 2008, VPs have all been announced heading into a weekend, although over the long term, there is no discernible preference in the data for any specific day of the week.)

As for Clinton, the safe call would be that she will make her pick the week before the convention—except this year, the RNC and DNC occur on consecutive weeks, so that would be directly in the middle of the RNC. While it might be tempting to steal some of Trump's thunder, the Clinton campaign would never announce during the RNC for fear that her pick, and the message he or she sends, would be drowned out in the news cycle. So when can she fit the announcement in?

Again, history holds the answer. Only twice since 1972 were the conventions on consecutive weeks: in 2008 and in 2012. In 2012, Democrats (whose convention was later) had no vice-presidential candidate to announce; everyone knew Joe Biden would be renominated. But in 2008, the Republican convention was second, but John McCain announced Sarah Palin the week before (and therefore the same week as the DNC) anyway—he just waited until Friday, when the DNC was over. This is a politically shrewd move; immediately after your opponent's convention is over, swoop in and steal their media cycle, hopefully putting a swift end to any residual coverage and honeymoon period they were enjoying.

This year, the RNC ends on Thursday, July 21, and the DNC doesn't begin until Monday, July 25. I think there's a strong chance Clinton will pull a McCain and reveal her running mate the Friday in between: July 22. Now the only question remains—who will it be?